While Apple had a lot of big, splashy announcements to make on stage at WWDC 2016, one that slipped under the radar was its development of a brand new file system. Called Apple File System (APFS), Apple refers to the system as a next-generation system for all of its products, ranging from Mac desktops down to watchOS.

Apple File System is a new, modern file system for iOS, OS X, tvOS and watchOS. It is optimized for Flash/SSD storage and features strong encryption, copy-on-write metadata, space sharing, cloning for files and directories, snapshots, fast directory sizing, atomic safe-save primitives, and improved file system fundamentals.

Apple goes on to note that the APFS is meant to replace the aging HFS+ file system, which, along with its HFS predecessor, are now more than 30 years old. APFS is available in developer preview in macOS Sierra (OS X 10.12), and is set to ship sometime in 2017.

If you're a developer who is interested in diving into the gritty details of what's new and different about APFS, you can read more in Apple's developer documentation. The Cupertino company is set to hold some sessions on the subject during WWDC this week as well.